U.S. patent number 8,415,645 [Application Number 12/657,491] was granted by the patent office on 2013-04-09 for apparatus and method for sterilizing vessel with electron beam.
This patent grant is currently assigned to Shibuya Kogyo Co., Ltd.. The grantee listed for this patent is Masami Hayashi, Toshiya Kobayashi, Mitsuomi Narita, Tokuo Nishi, Hideki Nishikawa, Yukinobu Nishino, Tomohiko Sugimori, Yukihiro Yamamoto, Tsunehiko Yokoi. Invention is credited to Masami Hayashi, Toshiya Kobayashi, Mitsuomi Narita, Tokuo Nishi, Hideki Nishikawa, Yukinobu Nishino, Tomohiko Sugimori, Yukihiro Yamamoto, Tsunehiko Yokoi.
United States Patent |
8,415,645 |
Kobayashi , et al. |
April 9, 2013 |
Apparatus and method for sterilizing vessel with electron beam
Abstract
It is aimed to prevent electrical charging inside a resin
material as well as a surface of a resin vessel at a time of
sterilizing the resin vessel by being irradiated with electron
beam. A bottle support unit is mounted to a lower end portion of a
cylindrical rotating shaft rotatably supported by a rotating wheel.
The bottle support unit includes a pair of griper members by which
a mouth portion of a bottle is gripped. The bottle rotated and
conveyed in a state supported by the bottle support unit is
irradiated with the electron beam from an electron beam irradiator
to thereby sterilize the bottle. A ground electrode is disposed to
be capable of being inserted into the interior of the resin vessel
through a mouth portion thereof, and the interior of the resin
vessel is irradiated with the electron beam in a state of the
ground electrode being inserted into the resin vessel. Since extra
electrons or ions generated by the irradiation to the resin vessel
with the electron beam flow outside, the charge amount of the resin
vessel is alleviated.
Inventors: |
Kobayashi; Toshiya (Tokyo,
JP), Narita; Mitsuomi (Tokyo, JP),
Sugimori; Tomohiko (Tokyo, JP), Yokoi; Tsunehiko
(Kumamoto, JP), Nishino; Yukinobu (Ishikawa,
JP), Hayashi; Masami (Ishikawa, JP),
Nishikawa; Hideki (Ishikawa, JP), Yamamoto;
Yukihiro (Ishikawa, JP), Nishi; Tokuo (Ishikawa,
JP) |
Applicant: |
Name |
City |
State |
Country |
Type |
Kobayashi; Toshiya
Narita; Mitsuomi
Sugimori; Tomohiko
Yokoi; Tsunehiko
Nishino; Yukinobu
Hayashi; Masami
Nishikawa; Hideki
Yamamoto; Yukihiro
Nishi; Tokuo |
Tokyo
Tokyo
Tokyo
Kumamoto
Ishikawa
Ishikawa
Ishikawa
Ishikawa
Ishikawa |
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A |
JP
JP
JP
JP
JP
JP
JP
JP
JP |
|
|
Assignee: |
Shibuya Kogyo Co., Ltd.
(Kanazawa-shi, Ishikawa, JP)
|
Family
ID: |
42102619 |
Appl.
No.: |
12/657,491 |
Filed: |
January 21, 2010 |
Prior Publication Data
|
|
|
|
Document
Identifier |
Publication Date |
|
US 20100202918 A1 |
Aug 12, 2010 |
|
Foreign Application Priority Data
|
|
|
|
|
Jan 22, 2009 [JP] |
|
|
2009-12306 |
Jun 30, 2009 [JP] |
|
|
2009-156097 |
|
Current U.S.
Class: |
250/492.3;
204/157.44; 204/193; 250/492.1; 250/455.11; 315/111.81;
313/107.5 |
Current CPC
Class: |
B65B
55/08 (20130101); B67C 7/0073 (20130101); A01N
1/0294 (20130101); A61L 2/087 (20130101); A61L
9/22 (20130101); A61L 2/00 (20130101); A61L
2202/10 (20130101); A61L 2/202 (20130101); A61L
2202/23 (20130101); A61K 41/00 (20130101) |
Current International
Class: |
G01N
23/00 (20060101); A61N 5/00 (20060101); H01J
43/00 (20060101); H01J 7/24 (20060101) |
Field of
Search: |
;422/6,14,22,23,28,33,186.05,186.29,186.3,305
;250/455.11,492.1,492.3 ;204/157.44,193 ;315/111.81 ;313/107.5 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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|
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|
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|
|
2000-68093 |
|
Mar 2000 |
|
JP |
|
2004-14319 |
|
Jan 2004 |
|
JP |
|
2007-126171 |
|
May 2007 |
|
JP |
|
Primary Examiner: Warden; Jill
Assistant Examiner: Chorbaji; Monzer
Attorney, Agent or Firm: Flynn, Thiel, Boutell & Tanis,
P.C.
Claims
What is claimed is:
1. An electron beam sterilizer for sterilizing a resin vessel,
comprising: an electron beam irradiator for irradiating the resin
vessel with an electron beam emitted from an electron beam
irradiator, and a ground electrode to be inserted into the resin
vessel through an opening thereof wherein the resin vessel is
irradiated with the electron beam in a state in which the ground
electrode is inserted into the resin vessel.
2. The electron beam sterilizer according to claim 1, wherein the
ground electrode is formed with a gas passage, and when the ground
electrode is inserted into the resin vessel to be irradiated with
the electron beam, an aseptic gas blows into the resin vessel
through the gas passage.
3. The electron beam sterilizer according to claim 1, wherein a
transfer means on which a plurality of resin vessels are
transferred is disposed, said transfer means transferring said
plurality of resin vessels to and away from said electron beam
irradiator, and a charge removing unit for removing charge from the
resin vessel is disposed on a downstream side of the electron beam
irradiator for irradiating the resin vessel with the electron beam
and removing the charge from the plurality of resin vessels in the
transfer path.
4. The electron beam sterilizer according to claim 2, wherein a
transfer means on which a plurality of resin vessels are
transferred is disposed, said transfer means transferring said
plurality of resin vessels to and away from said electron beam
irradiator, and a charge removing unit for removing charge from the
resin vessel is disposed on a downstream side of the electron beam
irradiator for irradiating the resin vessel with the electron beam
and removing the charge from the plurality of resin vessels in the
transfer path.
5. The electron beam sterilizer according to claim 1, wherein a
rotating means for rotating the resin vessel when the electron beam
is emitted from the electron beam irradiator is provided.
Description
FIELD OF THE INVENTION
The present invention relates to an apparatus for and a method of
irradiating resin vessels with electron beam to thereby sterilize
the vessels, and more particularly, to an electron beam irradiation
vessel sterilization apparatus and an electron beam irradiation
vessel sterilization method capable of preventing resin vessel from
being electrically charged by the irradiation with the electron
beam. This electron beam irradiation vessel sterilization apparatus
of the present invention may be simply called hereinlater as
"electron beam sterilizer".
BACKGROUND OF THE INVENTION
Apparatus for irradiating resin vessels such as PET bottles with
electron beam for sterilizing the same have been widely known in
conventional technology. It is also conventionally known that the
resin vessel is electrostatically charged by being irradiated with
the electron beam for sterilizing the vessel (for example, refer to
Japanese Patent Application Laid-open Publication No. 2007-126171:
Patent Publication 1).
This Patent Publication 1 discloses a PET bottle drink filling
system having a structure in which the PET bottle entering from an
entrance port is conveyed to a sterilization section by a food
vessel conveying device, and then, is sterilized by being
irradiated with the electron beam from an electron beam irradiating
device. The sterilized PET bottle is then conveyed to a wash-out
rinser so as to be cleaned by water or air. The PET bottle
discharged out of the rinser is filled up with inner content by a
filling device. The PET bottle filled up with the inner content is
then applied with a cap by a capper so as to seal the PET
bottle.
With the structure disclosed in the above Patent Publication 1,
since the PET bottle electrostatically charged with the irradiation
with the electron beam, it is necessary to arrange a charge amount
measuring device for detecting the charge amount, and the measured
charge amount is sent to a computer from the charge amount
measuring device to analyze the charge amount so as to judge
whether the charge amount of the PET bottle generated by the
irradiation with the electron beam is within a predetermined range
or out of range.
If the resin bottle is electrostatically charged, dirt or dust may
be attracted thereto, thus arising an inconvenient matter. Then,
various apparatus or devices have been conventionally proposed to
remove static electricity charging the resin vessels (for example,
refer to Japanese Patent Application Laid-open Publication Nos.
2000-68093 and 2004-14319: Patent Publications 2 and 3).
In the invention concerning a static electricity removing method
and apparatus disclosed in the above Patent Publication 2, the
static electricity is removed by irradiating a resin hollow vessel
with an X-ray. Further, in the invention concerning a static
electricity removing apparatus disclosed in the above Patent
Publication 3 is provided with a loop nozzle curved in form of loop
and formed with an air discharging port for discharging air against
an outer surface of a bottle and a straight nozzle formed with
another air discharging port for discharging air against an inner
surface of the bottle, and by blowing ionized air from these
nozzles to the outer and inner surfaces of the bottle to thereby
remove the static electricity charged on these surfaces.
It may be possible to reduce the charging on the inner and outer
surfaces of the resin vessel (bottle) by removing the static
electricity by the method and/or apparatus disclosed in the Patent
Publications 2 and 3. However, even by these method and apparatus,
it was difficult to remove the charge accumulated inside the resin
material (substance) itself forming the bottle.
SUMMARY OF THE INVENTION
The present invention was conceived in consideration of the
circumstances encountered in the prior art mentioned above and an
object thereof is to provide an apparatus and a method for
sterilizing a vessel with electron beam irradiation, i.e., electron
beam sterilizer, capable of preventing charge which may causes
inside a resin material forming the vessel as well as removing
charges stuck on inner and outer surfaces of the vessel.
The above and other objects can be achieved by providing, in one
aspect of the present invention, an electron beam sterilizer for
sterilizing a resin vessel by irradiating the resin vessel with
electron beam emitted from an electron beam irradiator, wherein the
electron beam sterilizer is provided with a ground electrode to be
inserted into the resin vessel through an opening thereof, and the
resin vessel is irradiated with the electron beam in a state in
which the ground electrode is inserted into the resin vessel.
According to the above aspects and preferred embodiments of the
present invention, the ground electrode is inserted into the resin
vessel at the time of sterilizing the resin vessel with the
electron beam, so that the resin vessel can be prevented from being
electrically charged.
In another aspect of the present invention, the above object can be
also achieved by providing an electron beam sterilization method
for sterilizing a resin vessel by irradiating the resin vessel with
electron beam emitted from an electron beam irradiator, the method
being characterized by inserting a ground electrode into an
interior of the resin vessel through an opening thereof and, in
this state, irradiating the resin vessel with the electron
beam.
In preferred embodiments of the above aspects, the ground electrode
may be formed with a gas passage, and when the ground electrode is
inserted into the resin vessel to be irradiated with the electron
beam, an aseptic gas blows into the resin vessel through the gas
passage.
According to the irradiation with the electron beam while blowing
the aseptic gas into the resin vessel, ozone generated by the
electron beam irradiation can be pushed out and hence removed from
the resin vessel as well as dust, dirt and the like, thus achieving
air-rinsing effect. Especially, if inactive gas is utilized as
aseptic gas, since oxygen density in the resin vessel is reduced,
the generation of the ozone can be further prevented. In addition,
the use of such aseptic gas does not give inferior effect to the
sterilization performance. Furthermore, the apparatus may be
provided with an ionizer for blowing out the ionized aseptic gas,
and in such case, the electrical charging on the inner surface of
the resin vessel can be further prevented in addition to the
function of the location of the ground electrode.
In a further aspect of the present invention, there is also
provided an electron beam sterilizer for sterilizing a resin vessel
by irradiating the resin vessel with electron beam emitted from an
electron beam irradiator, wherein the electron beam sterilizer is
provided with an insertion member to be inserted into the resin
vessel through an opening thereof, the insertion member having a
positive potential, and the resin vessel is irradiated with the
electron beam in a state in which the insertion member is inserted
into the resin vessel.
In these further aspect of the present invention, the insertion
member may be further provided so as to be connected to an anode to
which positive voltage is applied, so that the resin vessel can be
prevented from being electrically charged.
BRIEF DESCRIPTION OF THE DRAWINGS
In the accompanying drawings:
FIG. 1 is a plan view illustrating an entire arrangement of an
electron beam irradiation vessel sterilization apparatus (electron
beam sterilizer) according to a first embodiment of the present
invention;
FIG. 2A is an illustrated elevational section showing an essential
portion of a conveying wheel provided with a bottle holding unit,
and FIG. 2B is a plan view illustrating a mechanism for elevating a
ground electrode;
FIG. 3 is an enlarged view showing a state other than irradiation
with an electron beam in FIG. 2A;
FIG. 4 is a view explaining an ionizer provided for the conveying
wheel;
FIG. 5 is an illustrated elevational section, in a state
corresponding to FIG. 2A, of an electron beam irradiation vessel
sterilization apparatus (electron beam sterilizer) according to a
second embodiment of the present invention;
FIGS. 6A and 6B are a view showing an essential portion of an
electron beam irradiation vessel sterilization apparatus (electron
beam sterilizer) according to a third, in which FIGS. 6A and 6B
show states corresponding to FIGS. 2A and 2B, respectively; and
FIG. 7 is a view showing a state other than irradiation with an
electron beam in FIG. 6A.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Preferred embodiments of the present invention will be described
hereunder with reference to the accompanying drawings. Further, it
is to be noted that terms "upper", "lower", "right", "left" and
like terms are used herein with reference to the illustrations of
the drawings or an actual arrangement of an apparatus.
An apparatus for sterilizing a vessel by irradiation with an
electron beam (which may be called electron beam sterilizer or
vessel sterilizer) 1 according to a preferred embodiment of the
present invention includes a sterilization chamber 6 surrounded by
wall sections 4 made of lead so as to prevent electron beam or
X-ray from leaking outside at a time when a vessel 2 is irradiated
with the electron beam so as to sterilize the same.
The interior space of this sterilization chamber 6 is divided into
several sections (i.e., chambers) including: a carry-in chamber 10
positioned on an entrance (inlet) side into which a carry-in wheel
8 is disposed; a main chamber 14 in which a conveyance wheel 12 for
rotating and conveying the vessel 2 transferred from the carry-in
wheel 8; an irradiation chamber 20 positioned in front of the
electron beam radiator 16 and irradiates, with the electron beam,
the resin vessel 2 supported and conveyed by a bottle support unit
or mechanism 18 (FIG. 2A) provided for the conveyance wheel 12; and
a carry-out chamber 22 positioned to be continuous to an exist
(outlet) side of the irradiation chamber 20 (FIG. 1) and conveying
the resin vessel 2 which has been sterilized by the electron beam
irradiation while maintaining an aseptic condition thereof toward
the downstream side of the vessel conveying path.
These chambers 10, 14, 20 and 22 are defined by inner wall sections
24, 26 and 28, respectively. Further, these inside wall sections
24, 26 and 28 as well as outer wall sections 4 are formed with
openings each having a size through which the resin vessel 2 can be
transferred through these openings, respectively.
In this embodiment, the vessel sterilized by the electron beam
irradiation sterilizer 1 and filled up with an inner content such
as liquid in the following processes performed on the downstream
side thereof is a resin vessel such as PET bottle 2. This resin
vessel 2 has a shell (body) portion having substantially
quadrangular cross section, as simply illustrated in FIG. 1, and
also is provided with a tubular mouth portion 2a at an upper
portion of the shell portion. The resin vessel 2 as PET bottle is
further provided with a flanged portion 2b positioned below the
mouth portion 2a in a standing state. Such resin vessel 2 is
conveyed in a suspended state such that an upper or a lower portion
of this flanged portion 2b is held by a gripper, or a lower surface
side of this flanged portion 2b is supported by the bottle support
unit 18 or other support means.
The resin vessels 2 are continuously conveyed by an air conveyer,
not shown, are then separated at a predetermined interval by an
infeed screw or like, and thereafter, are conveyed into the
carry-in chamber 10 disposed on the entrance side of the
sterilization chamber 6.
The carry-in wheel 8 disposed in the carry-in chamber 10 is
provided with a plurality of grippers 30 arranged along the
circumferential direction at an equal interval from each other, and
each of the grippers 30 grips the upper portion of the resin vessel
2 above the flanged portion 2b thereof, which is then conveyed in
the gripped state.
The conveyance wheel 12 disposed in the main chamber 14 is provided
with a plurality of bottle support units (mechanism) 18 along the
circumferential direction at an equal interval from each other, and
each of the support units 18 supports the lower surface side of the
flanged portion 2b of the resin vessel 2, which is then conveyed.
The carry-in wheel 8 and the conveyance wheel 12 are synchronously
rotated, and the resin vessels 2 are transferred, at a transferring
position "A", to the respective bottle support units 18 of the
conveyance wheel 12 from the respective grippers 30 of the carry-in
wheel 8.
Each of the resin vessels 2 supported by the bottle support unit 18
of the conveyance wheel 12 and then rotated and conveyed passes
inside the irradiation chamber 20 during which the resin vessel 2
is subjected to the irradiation with the electron beam from the
electron beam irradiator 16 entirely along the longitudinal
(vertical) direction thereof, thus being sterilized.
The thus sterilized resin vessel 2 is conveyed into the carry-out
chamber 22 disposed continuously to the irradiation chamber 20 and
transferred to the carry-out wheel 34. A plurality of grippers 36
are arranged on the outer periphery of the carry-out wheel 34 along
the circumferential direction at an equal interval from each other,
and each of these grippers 36 grips the upper portion of the resin
vessel 2 above the flanged portion thereof held by the bottle
support unit 18 of the conveyance wheel 12 so as to receive the
resin vessel.
The carry-out wheel 34 is also synchronously rotated with the
conveyance wheel 12, and at the transferring position "B", the
resin vessel 2 is transferred to the gripper 36 of the respective
carry-out wheel 34 from each of the respective bottle support unit
18 of the conveyance wheel 12. The resin vessel 2 gripped by the
gripper 34 of the carry-out wheel 34 is transferred to a vessel
support means disposed in a chamber, not shown, adjacent to the
carry-out chamber 22 so as to be subjected to the next process.
As mentioned hereinbefore, the wall section 4 is formed with the
opening 4a at a portion corresponding to the irradiation chamber
20, and the electron beam irradiator (irradiation device) 16 is
mounted to this opening 4a. This electron beam irradiator 16 is
provided with a vacuum chamber (acceleration chamber), not shown,
for irradiating the resin vessel with the electron beam, and as is
known, a filament is heated in a vacuum state in this vacuum
chamber to generate thermal electrons, which are then accelerated
by high voltage to generate high speed electron beam, and the
generated electron beam is taken out into atmosphere through a
metallic window fail such as Ti attached to an irradiation window
16a of the electron beam irradiator 16 and then irradiates an
object to be treated (resin vessel 2 in this embodiment) to thereby
perform the sterilization process or like process.
Further, although not shown in FIG. 1, a beam shield 38 (FIG. 2A)
is disposed behind the resin vessel 2 subjected to the electron
beam irradiation from the electron beam irradiator 16.
In the following, constructions or structures of the bottle support
units or mechanisms 18 provided for the conveyance wheel 12 and a
ground electrode to be inserted into the resin vessel 2 at the
sterilization process will be briefly described with reference to
FIGS. 2A and 2B.
The conveyance wheel 12 is composed of a horizontal disk-shaped
plate 40, an annular rotational plate 41 fixed to the outer
periphery of the disk-shaped plate 40, and an annular intermediate
plate 42 disposed above the rotational plate 41 to be integrally
rotatable with the rotational plate 41.
A cylindrical rotating shaft 44 disposed in a perpendicular
orientation supports the outer peripheries of the rotational plate
41 and the annular intermediate plate 42 to be rotatable through
ball bearings 46 and 48, respectively, at an equal interval in the
circumferential direction.
A horizontal mount member 50 is fixed to the lower end portion of
the cylindrical rotating shaft 44. A pair of gripping members 52A,
52B (which are disposed on the front and rear side on the drawing
paper of FIG. 2A) are disposed on the lower side of the mount
member 50 so that the resin vessel 2 can be held directly below the
cylindrical rotating shaft 44.
In the bottle support unit 18, the paired gripping members 52A, 52B
are mounted to the lower end portions of a pair of leaf (plate)
springs 54A, 54B so as to hold the resin vessel by the urging force
of the leaf springs 54A, 54B.
A pinion gear 64 is fixed to the upper end portion of the
cylindrical rotating shaft 44, to which the bottle support unit 18
is mounted, projecting over the intermediate plate 42. Furthermore,
a vertically extending intermediate shaft 66 are supported to be
rotatably through ball bearings 68 and 70 at a portion raidally
inside of a position at which the cylindrical shaft 44 is
supported, of the annular rotational plate 41 and the annular
intermediate plate 42 fixed to the outer periphery of the
disk-shaped plate 40. A sector gear 72 is mounted to the upper end
portion of the intermediate shaft 66 at a level substantially equal
to that of the pinion gear 64 of the rotational shaft 44. The
sector gear 72 is formed with teeth facing radially outward of the
conveyance wheel 12 so as to be meshed with the pinion gear 64.
Incidentally, a perpendicular pin 74 is attached to an end portion
(left end in FIG. 2A) directing radially inward of the conveyance
wheel 12 so as to penetrate the sector gear 72, and a cam follower
76 is supported to an upper end portion of the perpendicular pin 74
to be rotatable. A tension coil spring 80 is interposed between the
lower end portion of the perpendicular pin 74 and a spring
receiving pin 78 fixed to an inner peripheral end of the
intermediate plate 42 so as to attract the end portion of the
sector gear 72 toward the radially inside of the conveyance wheel
12.
A circular stationary plate 82 is disposed above the disk-shaped
plate 40 of the conveyance wheel 12, and a cam 84 for swinging the
sector gear 72 is fixed to the outer periphery of the circular
stationary plate 82. An outer peripheral surface of this cam 84 is
formed as cam surface, along which the cam follower 76 moves while
rotating. According to the swing motion in the radial direction due
to the rotational movement of the cam follower 76, the sector gear
72 is rotated around the intermediate shaft 66 to thereby rotate
the pinion gear 64.
The bottle support unit 18 is mounted to the lower end portion of
the cylindrical rotating shaft 44 to the upper end of which the
pinion gear 64 is fixed. Then, when the pinion gear 64 is rotated
by the swinging motion of the sector gear 72, and the cylindrical
rotating shaft 44 disposed above the mouth portion 2a of the resin
vessel 2 is rotated, so that the resin vessel 2 supported and
conveyed by the bottle support unit 18 is rotated with its gravity
(own weight) axis being the center of the rotation. In this
embodiment, the pinion gear 64 is rotated by the rotation of the
sector gear 72 so as to rotate the resin vessel 2 in the forward
and reverse direction by about 180 degrees.
The mount member 50, mentioned hereinbefore, is formed with a
through hole 50a at a position vertically corresponding to an inner
hole 44a of the cylindrical rotating shaft 44. Further, a ceiling
surface and an outer peripheral surface of the conveyance wheel 12
are covered by a cover 88, and the upper portion of the pinion gear
64 reaches the cover 88 covering the ceiling surface of the
conveyance wheel 12 so as to seal a portion between the cover 88
and the upper portion of the pinion gear 64 in a slidable manner.
According to such structure as mentioned above, circular holes 44a
of the rotating shaft 44 and a circular hole 64a of the pinion gear
64 vertically penetrate the inside space surrounded by the
disk-shaped plate 40 and the cover 88 to thereby shut off the
internal environment surrounded by the disk-shaped plate 40 and the
cover 88 from an ambient environment maintained in an aseptic
state.
As shown in FIG. 2A, FIG. 2B or FIG. 3, the conveyance wheel 12 is
provided with a ground electrode 90 which is inserted into the
resin vessel 2, when the resin vessel 2 being conveyed by the
bottle support unit 18 is irradiated with the electron beam. The
ground electrode 90 is attached to a lower end portion of a
vertically extending support rod 92 in a manner such that the
ground electrode 90 and the support rod 92 elevate so as to
penetrate the circular hole 44a of the cylindrical rotating shaft
44 and the circular hole 64a of the pinion gear 64 fixed to the
upper portion of the shaft 44 and also penetrate the through hole
50a of the horizontal mount member 50 disposed below.
Hereunder, a structure or mechanism for carrying out the
elevational motion of the ground electrode 90 will be
explained.
A guide mechanism 94 is disposed in a vertically extending fashion
at a radially inside position to which the cylindrical rotating
shaft 44 is positioned above the cover 88. This guide mechanism 94
is, as shown in FIGS. 2A and 2B, provided with a vertically
extending guide member 96 and a plurality of guide rollers 98
mounted to a plurality of vertical portions of the guide member 96.
These guide rollers 98 are arranged in pairs at vertically
appropriate portions of the guide member 96, and an elevating rod
100 is elevated vertically in a manner supported by the guide
rollers 98 and the guide member 96. The support rod 92 and the
ground electrode 90, mentioned hereinabove, are mounted to the
lower end portion of the elevating rod 100 through a horizontal
mount member 102 so as to vertically elevate the ground electrode
90 in accordance with the elevating motion of the elevating rod
100.
This ground electrode 90 may be formed of a metal material such as
stainless steel, aluminium, titanium, or like, or other
electrically conductive materials. Furthermore, the ground
electrode 90 may have a round rod shape, or other shape having
rectangular, oblong or polygonal section, and moreover, it may be
formed so as to provide a saw-tooth shape provided with a number of
projections or brushes on its outer peripheral surface so as to
smoothly induce electric charges.
A horizontally arranged stationary member 103 is disposed above the
ceiling surface of the cover 88 independent from the conveyance
wheel 12, and an elevating cam 104 is attached to the outer
peripheral portion of the stationary member 103.
Incidentally, an elevatinal member 106 arranged horizontally is
fixed to the elevating rod 100 at a position higher than the
location of the mount member 102, and a cam follower 108 is
attached to a distal (front) end portion of this elevational member
106. This cam follower 108 rolls and moves on the upper surface
(cam surface) of the elevating cam 104 so as to carry out elevating
motion following the cam shape to thereby elevate the ground
electrode 90. When the cam follower 108 is pushed upward to the
most high position by the elevating cam 104, the lower end of the
ground electrode 90 takes a position above the mouth portion 2a of
the resin vessel 2 (FIG. 3), and on the other hand, when the cam
follower 108 is lowered most downward, the lower end of the ground
electrode 90 is inserted into the vessel 2 to take a position near
the bottom surface 2c of the resin vessel 2. Further, at this time,
the lowered end of the elevating rod 100 is restricted in its
downward movement by the abutment of the horizontal mount member
102 against a support member 110 fixed to the ceiling surface of
the cover 88, and the cam follower 108 stops at a height level not
contacting the cam surface of the elevating cam 104. In this
positional condition, the ground electrode 90 becomes conductive to
the cover 88 made of metal material through the support rod 92, the
mount member 102 and the support member 110, which are all formed
of conductive metal materials, to thereby create conductive
condition between the ground electrode 90 and the cover 88, and
thus, the electric charges flow from the ground electrode 90 toward
the cover 88.
After the resin vessel 2 supported and conveyed by the bottle
support unit 18 of the conveyance wheel 12 has been sterilized by
the irradiation with the electron beam from the electron beam
irradiator 16, the resin vessel 2 is transferred to the gripper 36
of the carry-out wheel 34 and then rotated and conveyed.
A soft X-ray type ionizer 112 as charge removing means is arranged
outside the vessel conveying path provided with the gripper 6 of
the carry-out wheel 34 (refer to FIG. 1 or 4). Since structure of
such soft X-ray type ionizer 112 is well known in the art,
explanation thereof will be omitted herein (for example, see Patent
Publication 2). In this embodiment, the soft X-ray ionizer 112 is
accommodated within an accommodation case 116 fixed onto a column
114. The soft X-ray ionizer 112 has a front surface side from which
soft X-ray is emitted, and this front surface is covered by a soft
X-ray permeable resin film 118.
In the electron beam irradiation vessel sterilization apparatus
(electron beam sterilizer) 1 of this embodiment, since the interior
of the sterilization chamber 6 is sterilized by a medical agent
(medicine), the soft X-ray ionizer 112 is accommodated within the
case 116 and is sealed with the resin film 118 to thereby prevent
the medicine from adhering to the ionizer 112. Note that the charge
removing means may be arranged above or below the conveying resin
vessel without limited to the shown arrangement on the side
position thereof.
The operation and function of the electron beam sterilizer 1 of the
structures mentioned above will be described hereunder.
The resin vessels 2 sterilized by the electron beam sterilizer 1
according to this embodiment are conveyed by a neck conveyer, not
shown, and separated by a predetermined pitch, respectively.
Thereafter, the resin vessels 2 are conveyed by a conveying wheel,
not shown, into the carry-in chamber 10 in the aseptic chamber 6
surrounded by the wall sections 4 made of lead. The carry-in wheel
8 disposed within the carry-in chamber 10 is provided with a
plurality of grippers 30 arranged in the circumferential direction
at an equal interval from each other, and these grippers grip the
upper side portions of the flanged portions 2b positioned on the
lower side of the tubular mouth portions 2a of the respective resin
vessels 2. The resin vessels 2 gripped and held by the grippers 30
are rotated and conveyed by the rotation of the carry-in wheel 8 to
the position "A" at which the resin vessels 2 are transferred to
the bottle support units 18 provided for the conveyance wheel 12
from the grippers 30 of the carry-in wheel 8, respectively.
The bottle support unit 18 is rotated and moved in a manner such
that one of the grip members 52A, 52B is directed forward in the
rotating direction and the other one thereof is directed rearward
in the rotating direction, and at the transferring position "A",
the mouth portion 2a of the resin vessel 2 gripped by the gripper
of the carry-in wheel 8 is pushed into a space between both the
grip members 52A and 52B.
Both the grip members 52A, 52B are mounted to the lower end
portions of the leaf springs 54A, 54B, respectively, and the space
between the gripper members 52A and 52B are opened by forcibly
pushing the mouth portion 2a of the resin vessel 2 into the space
therebetween so as to grip the same. Thereafter, both the leaf
springs 54A and 54B return to their original positions by own
spring force, and then, as shown in FIGS. 2A and 2B, hold the lower
side of the flanged portion 2b of the resin vessel 2 as well as
support the lower surface thereof.
According to the rotation of the conveyance wheel 12, the resin
vessels 2 supported respectively by the bottle support units 18 are
rotated and conveyed in an arrowed direction "R" in FIG. 1 and
enter the electron beam irradiation chamber 20. When each of the
resin vessels 2 is subjected to the electron beam irradiation in
the irradiation chamber 20, the ground electrode 90 has been
lowered by the operation of the elevating cam 104 to the position,
as shown in FIG. 2A, till the front end (lower end) thereof almost
reaches the bottom surface 2c of the resin vessel 2 from the
opening of the mouth portion 2a of the vessel 2. Further, in the
sections or portions other than this section now being irradiated
with the electron beam, the ground electrodes 90 are lifted upward
by the elevating cam 104, and the front ends thereof are positioned
above the mouth portions 2a of the resin vessels 2 in the state
shown in FIG. 3. As mentioned above, during the movement of the
resin vessel 2 into which the ground electrode 90 is inserted in
the front side of the irradiation window 16a of the electron beam
irradiator 16, the resin vessel 2 is sterilized by the electron
beam irradiation.
If the resin vessel 2 into which the ground electrode 90 is not
inserted is irradiated with the electron beam, the resin vessel 2
is charged with electrons. However, by inserting the ground
electrode 90 into the resin vessel 2 at the time of the electron
beam irradiation such as in this embodiment, the electrons emitted
by the electron beam irradiation penetrate the resin material of
the vessel 2 and enter the interior of the resin vessel 2 through
the opening of the mouth portion 2a of the vessel 2. Then, the
electrons are induced by the ground electrode 90 and flow entirely
of the apparatus from the cover 88 through the support rod 92, the
mount member 102 and the support member 110, and accordingly, the
charging on the inner surface of the resin vessel 2 and interior of
the resin material of the vessel 2 can be effectively prevented.
Especially, the electrons emitted toward the outer surface of the
resin vessel 2 acts so as to permeate the resin material not only
by the penetrating force by the acceleration at the electron beam
irradiation time but also by the induction of the ground electrode
90 from the inside of the resin vessel 2, thus staying inside the
resin material and hence preventing it from being charged.
Further, the pinion gear 64 is fixed to the upper end portion of
the cylindrical rotating shaft 44, to which the bottle support unit
18 is attached, and is meshed with the sector gear 72, which is
engaged with the cam 84 mounted to the outer periphery of the
stationary plate 82 to be swingable. During the movement of the
cylindrical rotating shaft 44 in front of the electron beam
irradiator 16 by the operation of the cam 84, the cylindrical
rotating shaft 44 is rotated to thereby rotate the resin vessel 2
supported by the bottle support unit 18 by 180 degrees in forward
and reverse directions. As mentioned above, by the rotation of the
resin vessel 2 by 180 degrees in front of the irradiation window
16a of the electron beam irradiator 16, the resin vessel 2 can be
irradiated with the electron beam and, hence, sterilized entirely
in both the vertical and conveyance directions. The cylindrical
rotating shaft 44, the pinion gear 64, the sector gear 72 and the
cam 84 constitute a rotating means for rotating the resin vessel 2
defined by claims 5 and 13.
As described above, the ground electrode 90 is inserted into the
center portion in the resin vessel 2 and irradiated with the
electron beam, so that it is difficult to irradiate the electron
beam to the rear side of the ground electrode 90 because of shading
in itself. Although the electron beams emitted from the electron
beam irradiator go rectilinear as a whole, some measure of these
electron beams collide with the resin vessel 2 and an atmospheric
molecule. Accordingly, the body portion of the resin vessel having
a relatively wide space to the ground electrode 90 can be
indirectly irradiated with electron beam. On the other hand, the
neck portion of the resin vessel having a relatively narrow space
to the electrode 90 is hardly irradiated with electron beam to the
rear side thereof. Therefore, the rotation of the resin vessel 2 by
the above rotating means can make the whole of the resin vessel 2
irradiated with electron beam effectively.
The resin vessel 2 irradiated and sterilized with the electron beam
during the passing inside the irradiation chamber 20 is rotated and
conveyed in the state supported by the bottle support unit 18 from
the irradiation chamber 20 to the carry-out chamber 22. The
carry-out wheel 34 is disposed inside the carry-out chamber 20, and
the resin vessel 2 which is supported by the bottle support unit 18
at the lower side of the flanged portion 2b is transferred to the
gripper 36 provided for the carry-out wheel 34 so as to grip the
upper side of the flanged portion 2b of the resin vessel 2. The
resin vessel 2 rotated and conveyed in the state supported by the
gripper 36 of the carry-out wheel 34 then reaches the position of
the soft X-ray ioniser 112, which acts to ionise the atmosphere
around the electrically charged object (resin vessel 2 in this
embodiment) by the soft X-ray irradiating energy and neutralise the
static electricity. At the time of the electron beam irradiation by
the electron beam irradiator 16, the inner surface and the inside
of the resin material forming the resin vessel 2 are prevented from
being electrically charged by the insertion of the ground electrode
90 into the resin vessel 2, and in addition, the irradiation of the
soft X-ray by the soft X-ray ioniser 112 to the resin vessel 2
after the electron beam irradiation can remove the charging on the
outer surface of the resin vessel 2.
Hereunder, a second embodiment of an electron beam irradiation
vessel sterilization apparatus (electron beam sterilizer) 101 will
be described with reference to FIG. 5 showing arrangement or
structure corresponding to FIG. 2A which represents the first
embodiment.
The electron beam sterilizer 101 of this second embodiment has a
basic structure similar to that of the first embodiment, and
differs in a structure or type a gas passage for blowing aseptic
gas into an interior of the resin vessel 2 at the time of the
electron beam irradiation, and therefore, hereunder, only such
different structure will be explained, and like reference numerals
are added to members and portions corresponding to those of the
first embodiment and duplicated description is omitted herein.
In this second embodiment, a ground electrode 190 and a support rod
192 disposed above the ground electrode 190 have hollow structures
so as to form gas passages through which gas flows.
In addition, an aseptic gas supply source, not shown, provided with
an aseptic filter such as HEPA filter is connected to an upper end
portion of the support rod 192. In this embodiment, when the resin
vessel 2 is sterilized by the electron beam irradiation from the
electron beam irradiator 16, as like as in the first embodiment,
the ground electrode 190 has been inserted into the resin vessel 2,
and during the irradiation of the electron beam, the gas such as
air or inactive gas such as nitrogen or argon passing through the
aseptic filter blows out from a blow-out port 190a formed to the
front end of the ground electrode 190 into the resin vessel 2.
As mentioned above, by performing the electron beam irradiation
while blowing out the aseptic gas to a portion near the bottom
portion of the resin vessel 2, ozone generated by the electron beam
irradiation is pushed out and removed from the opening of the mouth
portion 2a of the vessel 2 as well as dirt and dust, thus
effectively performing air-rinsing effect. Particularly, when the
inactive gas is utilized, since oxygen density inside the resin
vessel 2 is lowered, the effect of preventing the ozone generation
can be further improved, and in addition, the aseptic gas does not
reduce the sterilization effect. Still furthermore, by blowing out
the aseptic gas ionised by an ionising device, the electrical
charging on the inside surface of the resin vessel 2 can be further
prevented in addition to the function of the ground electrode 190
itself. In such occasion, since the resin vessel 2 is negatively
charged by the irradiation of the electron beam, in order to
neutralize this state, the blow-out of positive ion may be
effective. Furthermore, the irradiation of the electron beam
generates nitrogen oxide, which will be dissolved into water
content in the air and may generate nitric acid, and since such
nitric acid corrodes the apparatus, in order to prevent such
adverse phenomenon, it is desirable to blow out sufficiently dried
dry aseptic gas.
In the embodiments described above, the resin vessel 2 is
irradiated with the electron beam in the state in which the ground
electrode 90 or 190 is inserted into the resin vessel 2, and the
emitted electrons flow from the ground electrode 90 or 190 toward
the cover 88. However, the present invention is not limited to such
embodiments.
FIGS. 6A and 6B are an elevational section of an essential portion
of an electron beam irradiation vessel sterilization apparatus
(electron beam sterilizer) 201 according to a third embodiment of
the present invention. This third embodiment differs from the
aforementioned embodiments in the structure of a member to be
inserted into the resin vessel at the time of the electron beam
irradiation, and like reference numerals are added to members and
portions corresponding to those of the first or second embodiment
and duplicated description is omitted herein.
In this third embodiment, the carry-in wheel 12 is provided with an
insertion member (positive potential rod) to be inserted into the
interior of the resin vessel 2 at the time of the electron beam
irradiation to the resin vessel 2 being conveyed by the bottle
support unit 18.
The positive potential rod 290 is attached to the lower end portion
of a vertically arranged support rod 292, and these positive
potential rod 290 and the support rod 292 are arranged so as to
penetrate and elevate the cylindrical rotating shaft 44, pinion
gear 64 fixed to the upper end thereof, the circular holes 44a and
64a, and the through hole 50a of the horizontal mount member 50
disposed below.
A structure for elevating the positive potential rod 290 will be
described hereunder.
As shown in FIG. 6A, the vertically extending guide mechanism 94 is
disposed radially inside of the location of the cylindrical
rotating shaft 44 above the cover 88. This guide mechanism 94 shown
in FIGS. 6A and 6B has substantially the same structure of that of
the first embodiment shown in FIGS. 2A and 2B. A horizontal mount
plate 202 is fixed to the lower end portion of the elevating rod
100 of the guide mechanism 94 through an insulating member 210, and
the support rod 292 and the positive potential rod 290 are attached
through the horizontal mount plate 202 so that the positive
potential rod 290 is elevated by the elevating motion of the
elevating rod 100. Further, the positive potential rod 290 may be
made of electrically conductive substance or metal such as
stainless steel, aluminium, titanium or the like, or other
conductive material. Furthermore, the positive potential rod 290
may have a shape such as round shape, or rectangular shape, oblong
shape or polygonal shape in section, or a saw-tooth shape having a
number of projections formed on an outer periphery thereof, or a
shape provided with brush, which will provide readily charge
induction function.
When the cam follower 108 of the guide mechanism 94 is pushed
upward to the uppermost position by the elevating cam 104, the
lower end portion of the positive potential rod 290 takes a
position above the mouth portion 2a of the resin vessel 2 as shown
in FIG. 7, and on the other hand, when the cam follower 108 is
pushed downward to the lowermost position, the lower end portion of
the positive potential rod 290 is inserted into a portion near the
bottom surface 2c of the resin vessel 2.
The positive potential rod 290 is operatively connected to a
positive electrode 224, to which positive potential is applied,
through the upper support rod 292, the horizontal mount member 202,
an expansion coil 220 disposed between the lower surface of the
mount member 202 and the cover 88, and a conductive wire 222. The
positive potential is always applied to this positive electrode 224
during the operation of the apparatus, and since the insertion
member 290 is in a state applied with the positive potential, this
insertion member 290 is called "positive potential rod 290" herein
with respect to this embodiment.
Next, the operation of the electron beam irradiation vessel
sterilization apparatus (electron beam sterilizer) according to
this embodiment will be described.
According to the rotation of the conveyance wheel 12, the resin
vessel 2 supported by the bottle support unit 18 enters the
electron beam irradiation chamber 20 in which the resin vessel 2 is
subjected to the electron beam irradiation. When the resin vessel 2
is irradiated with the electron beam in this irradiation chamber
20, the positive potential rod 290 has been lowered by the
operation of the elevating cam 104, and as shown in FIG. 6A, the
front end (lower end) of the rod 290 is inserted into a position of
the level near the bottom surface 2c of the resin vessel 2 through
the opening of the mouth portion 2a thereof.
Further, in the sections or areas other than that in which the
resin vessel 2 is irradiated with the electron beam, the positive
potential rods 290 are elevated upward by the elevating cams 104
such that the front (lower) ends of the potential rods 290 are
positioned above the openings of the mouth portions 2a of the resin
vessels 2, respectively, in the state shown in FIG. 7. In the
manner mentioned above, the resin vessel 2, into which he positive
potential rod 290 is inserted, is irradiated with the electron beam
during the passing in front of the irradiation window 16a of the
electron beam irradiator 16, thus being sterilized. On the other
hand, if the resin vessel 2, into which the positive potential rod
290 is not inserted, is irradiated with the electron beam, the
resin vessel 2 will be charged with electrons. However, as in this
embodiment, by inserting the positive potential rod 290 into the
resin vessel 2 at the time of the electron beam irradiation, the
emitted electrons penetrate or permeate the inside resin material
of the resin vessel 2 and enter the resin vessel 2 through the
opening of the mouth portion 2a of the resin vessel 2, and then,
the electrons flow by the induction of the positive potential rod
290. Accordingly, the inner surface of the resin vessel 2 and the
interior of the resin material forming the vessel 2 can be
prevented from being electrically charged. Particularly, the
electrons emitted toward the outer surface of the resin vessel 2
penetrate or permeate the resin material not only by the
penetration force due to acceleration at the time of the electron
beam irradiation but also by the induction to the positive
potential rod 290 from the inside of the resin vessel 2, whereby
the electrons stay inside the resin material and, thus, the resin
vessel 2 is prevented from being electrically charged.
Further, it is to be noted that, although, in the described
embodiment, the insertion member 290 is connected to a positive
electrode so as to provide positive potential, it is always not
necessary to be connected to the positive electrode, and it may be
possible to preliminarily charge the insertion member 290 with
positive electric charges. For example, it may be possible to
generate static electricity to the insertion member 290 by friction
it to create a positively charged state, and in such case, an
effect substantially identical to that obtained in the case of the
connection of the positive electrode is obtainable. In the case
where the insertion member 290 is connected to the positive
electrode, the electrons flow outside the resin vessel 2 through
the insertion member 290, but in the case where the insertion
member 290 is preliminarily charged, the electrons may be attracted
to the positive charges.
Furthermore, in this embodiment, as like as the second embodiment,
it may be possible to form a gas passage through which the gas
flows in the interiors of the positive potential rod 290 and the
support rod 292 disposed above the potential rod 290, to connect
the gas passage to an aseptic gas supply source provided with an
aseptic filter such as HEPA filter and to blow out, from the front
end of the positive potential rod 290, the gas composed of air or
inactive gas such as nitrogen or argon passing through the aseptic
filter from the positive potential rod 290 inserted into the resin
vessel 2 during the electron beam irradiation. In such case,
substantially the same effects as those attained by the second
embodiment may be attained.
It is further to be noted that the present invention is not limited
to the described embodiments and many other changes and
modifications may be made, such as those mentioned above, without
departing from the scope of the appended claims.
* * * * *